Mr Colin Egerer (William and Mary)
An understanding of the partonic structure of hadrons is an essential ingredient in making precise predictions and measurements of hadronic cross-sections and various Standard, and Beyond Standard, Model parameters. Direct first-principles calculations of parton distribution functions (PDFs) via lattice QCD were historically limited to the lowest few moments, principally due to the time-dependence of PDFs and the breaking of rotational symmetry. Several encouraging proposals have since been developed that relate lattice calculable quantities with PDFs via frameworks akin to QCD factorization. We present the first lattice QCD calculations of one such proposal, wherein the pion valence quark distribution is obtained from a renormalizable and factorizable matrix element of an antisymmetric combination of vector and axial-vector current-current correlations of fixed spatial separation. The valence distribution is extracted by considering the NLO perturbative kernel for this current combination, thereby giving better control over corrections in the spatial separation. Results are presented for several lattice ensembles, with an eye towards proper chiral, continuum, and infinite volume limits.
Mr Colin Egerer (William and Mary) Joseph Karpie (College of William and Mary) Raza Sufian (Jefferson Lab)
Dr David Richards (Jefferson Lab) Dr Jianwei Qiu (Jefferson Lab) Prof. Kostas Orginos (William and Mary / JLab)